The betting firm tweeted: "Following recent allegations made against Luis Suárez, we are reviewing our relationship with him. We will not tolerate unsporting behavior."

FIFA have opened disciplinary proceeding against the striker after reviewing the footage of the incident with Chiellini.

In November 2010 Suarez was banned for seven matches for biting PSV Eindhoven defender Otman Bakkal on the shoulder during an Dutch league match.

He moved to Liverpool in January 2011 and repeated the crime in April 2013 when he bit Chelsea defender Branislav Ivanovic during a 2-2 draw at Anfield, for which the Uruguayan was handed a 10-game ban.

He was also found guilty of racially abusing Manchester United defender Patrice Evra in 2011.

Suarez was handed an eight-match ban and fined £40,000.

More controversy was to follow in the next meeting between the sides when Suarez refused to shake Evra's hand pre-match.

He was also banned for one game and fined £20,000 for making an obscene gesture towards Fulham fans in December 2011.